Several privacy groups have raised alarms over plans by the U.S. Office of Personnel Management (OPM) to build a database that would contain information about the healthcare claims of millions of Americans.

The concerns have surfaced because the OPM has provided few details about the new database and because the data collected will be shared with law enforcement, third-party researchers and others.

In a letter to OPM Director John Berry, the Center for Democracy and Technology (CDT) and 15 other organizations asked the agency to release more details on the need for the database and how the data contained in it will be protected and used.

The OPM “should not create this massive database full of detailed individual health records without giving the public a full and fair chance to evaluate the specifics of the program,” the letter cautioned.